We have asked this before and we have to ask it again: Is Justin Bieber losing it completely?

Hours after arriving back from a series of concerts in Europe the 19-year-old Baby singer has been accused of battering a neighbour.

The teenage popstar arrived at his Calabasas, California home in the morning, after being photographed strolling shirtless through a Polish airport the night before.

TMZ reports Bieber was involved in the fight soon after he settled in, when a resident from his neighbourhood came on to his property to call attention to a grievance.

According to the news site the singer had a Ferrari delivered to his home last night on a flatbed truck (as you do) and this morning, he was racing the vehicle up and down the streets.

The neighbour, furious about the deafening noise and concerned Bieber was endangering the community by racing through the streets, reportedly got into a heated verbal altercation.

The man in question accuses the pop star of making physical contact with him.

Los Angeles County Sheriff spokesperson Steve Whitmore told the website a battery report had been filed and officials were investigating whether Bieber threatened the alleged victim during the incident.

No charges have been filed against the Canadian pop star and Whitmore declined to give details, citing an ongoing investigation. Under California law, a misdemeanor battery charge can include unwanted touching or spitting.

The Canadian singer had previously been spotted wearing a bizarre gas mask on a night out in London, where he turned up late for one concert and collapsed on stage with shortness of breath during another.

After a sold out concert in Lodz, central Poland, the 19-year-old took off his shirt in a car as it drove up to the airport late in the night on Monday.

He then walked topless with his pants almost on the ground to the airport building - in temperatures of about -10C (14F) - and then on to his gate, only to get dressed again before boarding a private jet.

"He wasn't told to take off his clothes. He had no metal objects on him," a spokeswoman for Lodz Airport said. "He's quite skinny so I assume he was probably freezing."

The concert's organisers put the incident down to a Bieber eccentricity.

The show in Lodz was the 19th European concert of Bieber's Believe tour. The next one is due to take place in Munich, Germany, on March 28.